Modify wording based on comments on August 3rd

csi.proto

@@ -383,10 +383,14 @@ message CreateVolumeRequest {
   // choose where the provisioned volume is accessible from.
   TopologyRequirement accessibility_requirements = 7;
 
-  // Plugin specific parameters to apply, passed in as opaque
-  // key-value pairs. This field is OPTIONAL. The Plugin is
-  // responsible for parsing and validating these parameters. 
-  // COs will treat these as opaque. Plugins MUST treat these 
+  // Plugin specific creation-time parameters passed in as opaque 
+  // key-value pairs. These mutable_parameteres MAY also be
+  // changed during the lifetime of the volume via a subsequent
+  // `ControllerModifyVolume` RPC. This field is OPTIONAL.
+  // The Plugin is responsible for parsing and validating these
+  // parameters. COs will treat these as opaque.
+
+  // Plugins MUST treat these 
   // as if they take precedence over the parameters field.
   // This field SHALL NOT be specified unless the SP has the
   // MODIFY_VOLUME plugin capability.
@@ -1009,8 +1013,9 @@ message ControllerModifyVolumeRequest {
   // section on how to use this field.
   map<string, string> secrets = 2 [(csi_secret) = true];
 
-  // Plugin specific parameters to apply, passed in as opaque key-value
-  // pairs. This field is REQUIRED. The Plugin is responsible for
+  // Plugin specific volume attributes to mutate, passed in as 
+  // opaque key-value pairs. 
+  // This field is REQUIRED. The Plugin is responsible for
   // parsing and validating these parameters. COs will treat these
   // as opaque. The CO SHOULD specify the intended values of all mutable
   // parameters it intends to modify. SPs MUST NOT modify volumes based

spec.md

@@ -854,10 +854,14 @@ message CreateVolumeRequest {
   // choose where the provisioned volume is accessible from.
   TopologyRequirement accessibility_requirements = 7;
 
-  // Plugin specific parameters to apply, passed in as opaque
-  // key-value pairs. This field is OPTIONAL. The Plugin is
-  // responsible for parsing and validating these parameters. 
-  // COs will treat these as opaque. Plugins MUST treat these 
+  // Plugin specific creation-time parameters passed in as opaque 
+  // key-value pairs. These mutable_parameteres MAY also be
+  // changed during the lifetime of the volume via a subsequent
+  // `ControllerModifyVolume` RPC. This field is OPTIONAL.
+  // The Plugin is responsible for parsing and validating these
+  // parameters. COs will treat these as opaque.
+  
+  // Plugins MUST treat these 
   // as if they take precedence over the parameters field.
   // This field SHALL NOT be specified unless the SP has the
   // MODIFY_VOLUME plugin capability.
@@ -1667,8 +1671,9 @@ message ControllerModifyVolumeRequest {
   // section on how to use this field.
   map<string, string> secrets = 2 [(csi_secret) = true];
 
-  // Plugin specific parameters to apply, passed in as opaque key-value
-  // pairs. This field is REQUIRED. The Plugin is responsible for
+  // Plugin specific volume attributes to mutate, passed in as 
+  // opaque key-value pairs. 
+  // This field is REQUIRED. The Plugin is responsible for
   // parsing and validating these parameters. COs will treat these
   // as opaque. The CO SHOULD specify the intended values of all mutable
   // parameters it intends to modify. SPs MUST NOT modify volumes based